L-Glutamine is produced in the body and is the most abundant protein in the blood and other bodily fluids. However, highly active individuals usually have higher Glutamine needs than their bodies can produce. Therefore, supplementing with it is essential for those wanting to perform better.  L-Glutamine supports lean muscle mass, cell growth, and growth hormone release in the body, which is essential for improved performance. It also boosts the immune system activity in the gut, helping to prevent infection. Ingredients: L-Glutamine Powder. Flavor: Unflavored Manufacturer Country: USA Product Amount: 0.66lb (300g) Gross Weight: 0.